The present invention relates to a method of and a mechanism for attaching and detaching an automobile door, and more particularly to a method of and a mechanism for attaching and detaching an automobile door by temporarily placing hinge pins on ends of hinge members on an automobile body. Thereafter, the hinge members are aligned on an automobile door with the hinge members on the automobile body with an assembling mechanism including door holder means. The hinge pins are pushed into the aligned hinge members to temporarily mount the door on the automobile body easily and reliably for the purpose of painting the door and the body together. After the door and the body have been painted, the hinge pins are automatically removed with hinge pin remover means and the door holder means to detach the door from the automobile body for the purpose of rigging the automobile body.
On automobile production lines, an automobile body and doors that are assembled are painted together in order to eliminate any irregular paint coating, then the doors are detached from the body for the purpose of outfitting the body, and thereafter the body and the doors are assembled together.
There has been employed a holder device for positioning and holding the door so that hinge members of the door and the body, after they have been rigged, will be suitably positioned relatively to each other for properly assembling the door and the body together. The holder device first positions the door while using the lower edge of the door as a reference. At this time, the door is held in position by utilizing an outer door portion including the lower edge of the door, or a door surface which will be positioned outside when the door is mounted on the body. More specifically, the lower edge of the door and the outer door portion are held by the holder device, and the holder device is moved toward the body to bring the hinge members of the door into engagement with the hinge members of the body. After hinge pins have been inserted into the hinge members, retaining means are attached to the hinge pins to couple the door to the body. Door holder jigs on the holder device are shaped complementarily to the configurations of the lower edge of the door and the outer door portion.
As described above, the hinge pins are inserted into the hinge members on the body and the door, and the retaining means are attached to the hinge pins to prevent them from dropping. Since the insertion of the hinge pins and the attachment of the retaining means are effected in a very small space between the body and the door, the efficiency is poor and the rate of production is lowered
Japanese Utility Model Publication No. 58(1983)- 17104 discloses an arrangement in which a hinge pin can be retained in place simply by inserting the hinge pin into a hinge member. More specifically, the hinge pin has a peripheral groove defined near one end thereof, and hinge pin retaining means can engage in the peripheral groove. The hinge pin retaining means comprises a ring-shaped member having one end smaller in diameter than the hinge pin and the opposite end larger in diameter than a hole defined in the hinge pin. The ring-shaped member has a recess extending axially to make the opposite end thereof resilient diametrically.
When the hinge pin and the hinge pin retaining means are inserted into the hole of the hinge member, the larger-diameter portion of the hinge pin retaining means is resiliently contracted diametrically upon passage through the hole of the hinge member. After the larger-diameter portion of the hinge pin retaining means has passed through the hole, it springs back to a diameter larger than the diameter of the hole. Even if the hinge pin inserted through the hinge members of the body and the door is moved in a direction to come off, one end of the larger-diameter portion of the hinge pin retaining means on the hinge pin engages the hinge member, thus preventing the hinge pin from dropping off.
With the hinge pin and the hinge pin retaining means constructed as above, however, the hinge pin is liable to be tilted with respect to the hinge member. Therefore, an undue load has to be applied to insert the hinge pin, or the hinge pin cannot be inserted in place.
Moreover, the hinge pin and the hinge pin retaining means are not suitable for automatic insertion of the hinge pin since it would be difficult to provide means for holding the hinge pin, and hence the projection efficiency is low.
Inasmuch as automobile doors are different in shape from automobile type to automobile type, as many differently shaped door holder jigs as the number of automobile types to be produced are required. Stocking such many different door holder jigs is not only uneconomical but also needs a large storage space. This is disadvantageous from the standpoint of effective utilization of small spaces, and also in that automatic production is interrupted by replacement of door holder jigs, resulting in a low production rate. Where a door is held at its outer surface by a door holder jig, the paint coating on the outer door surface may be damaged by the door holder jig, and the damaged door cannot be shipped as a product. Repainting the door may produce paint coating irregularities.
It has been customary to manually pull out a hinge pin for detaching a temporarily mounted door from an automobile body. Since the hinge pin is pulled out in a very limited space between the door and the body, however, the efficiency is bad and the rate of production is reduced.